DVC Civil Construction

Failed concrete block retaining wall

written by De Vries Cronje

I received a phone call during October 2011, from a not so happy resident in Plettenberg Bay    ( Magnetien Street ). He informed me that he had incurred damages due to a failed retaining wall. He could furthermore not locate the contractor who has done the installation as he has left the country. He requested that I do a site visit.

On my arrival I was not at all surprised on what I have founded, as it was not the first time that I had to quote for repairs on work done by this company / individual. This was a typical scenario which I have found at many victimised home owners through the years.

This retaining wall was build using blocks which the contractor has manufactured himself and not at all in line with the specification laid down by the Concrete Manufacturers Association of South Africa http://www.cma.org.za/.

The most basic principals in building a concrete block retaining wall was absent. No concrete footing, no water management behind or on top of wall, no free draining material used for back fill and no compaction of filling was done.

A worrying fact was that there was no engineer's certificate issued for this wall and this makes me wonder how the Bitou Municipality, http://www.plett.gov.za/ , issued the occupancy certificate for this house as a certificate is needed for any dry stack retaining wall structure regardless of the height since 2009. This project was completed in 2010.


I include some pictures of the failed retaining wall build by Chris Viljoen of Vilco Retaining Walls :

http://www.linkedin.com/in/cviljoen